Field of the Invention
The present invention relates to a method of securing an illumination or lighting fixture to the ceiling of a room by suspending the same from a slab of a building structure.
2. Prior Art Statement
In order to fixedly securing secure lighting fixtures in office and other buildings, there has hitherfore been employed a method wherein lighting fixtures are suspended from a slab of the building while using bolts and nuts for fixing the lighting fixtures at desired heights. In this known method, a straight bolt is cut to have a length measured to extend from the surface of the ceiling finish board to the slab, applied with rustproof treatment and then secured to the slab. A guide assembly having a chain for raising a support plate or housing for the lighting fixture is then attached to the bolt, followed by adjustment of the height, and then the support plate or housing is raised. After removing the guide assembly, a nut and a washer are fitted on the bolt and then the nut is threaded so that it moves upwards to fix the lighting fixture.
However, this known method has disadvantages in that a cumbersome and dangerous operation is necessary for fixing the lighting fixture resulting in reduction in operation efficiency, since the relatively heavy lighting fixture, must be supported by the hands of at least two workers' hands who are staying on high stepladders and the lighting fixture must be raised and lowered by them to adjust the height of the lighting fixture so that it is snugly fitted over an opening of the ceiling finish board. The known method has a further problem that an additional anchor must be driven in the slab at a different position in a case where there is a gap between the existing anchor for suspending the bolt from the slab and the opening of the ceiling finish board.